content: /*
   * Copyright 2016-present David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.rxjava3.basetypes;
  
  import java.util.*;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.exceptions.Exceptions;
  import io.reactivex.rxjava3.internal.subscriptions.*;
  import io.reactivex.rxjava3.internal.util.AtomicThrowable;
  
  /**
   * Subscribe to the Nono sources one at a time and complete if all of them complete.
   */
  final class NonoConcatIterable extends Nono {
  
      final Iterable<? extends Nono> sources;
  
      final boolean delayError;
  
      NonoConcatIterable(Iterable<? extends Nono> sources, boolean delayError) {
          this.sources = sources;
          this.delayError = delayError;
      }
  
      @Override
      protected void subscribeActual(Subscriber<? super Void> s) {
          Iterator<? extends Nono> it;
  
          try {
              it = Objects.requireNonNull(sources.iterator(), "The sources Iterable returned a null Iterator");
          } catch (Throwable ex) {
              Exceptions.throwIfFatal(ex);
              EmptySubscription.error(ex, s);
              return;
          }
  
          ConcatSubscriber parent = new ConcatSubscriber(s, it, delayError);
          s.onSubscribe(parent);
          parent.drain();
      }
  
      static final class ConcatSubscriber extends BasicRefQueueSubscription<Void, Subscription> implements Subscriber<Void> {
  
          private static final long serialVersionUID = -4926738846855955051L;
  
          final Subscriber<? super Void> downstream;
  
          final AtomicThrowable errors;
  
          final Iterator<? extends Nono> iterator;
  
          final AtomicInteger wip;
  
          volatile boolean active;
  
          ConcatSubscriber(Subscriber<? super Void> downstream, Iterator<? extends Nono> iterator, boolean delayError) {
              this.downstream = downstream;
              this.iterator = iterator;
              this.errors = delayError ? new AtomicThrowable() : null;
              this.wip = new AtomicInteger();
          }
  
          @Override
          public void cancel() {
              SubscriptionHelper.cancel(this);
              if (errors != null) {
                  errors.tryTerminateAndReport();
              }
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              SubscriptionHelper.replace(this, s);
          }
  
          @Override
          public void onNext(Void t) {
              // not called
          }
  
          @Override
          public void onError(Throwable t) {
              AtomicThrowable err = errors;
              if (err != null) {
                  if (err.tryAddThrowableOrReport(t)) {
                      active = false;
                      drain();
                  }
              } else {
                  downstream.onError(t);
              }
          }
  
          @Override
          public void onComplete() {
              active = false;
              drain();
          }
  
          void drain() {
              if (wip.getAndIncrement() != 0) {
                  return;
              }
  
              do {
                  if (SubscriptionHelper.CANCELLED == this.get()) {
                      return;
                  }
  
                  if (!active) {
                      boolean b;
                      Nono np = null;
  
                      try {
                          b = iterator.hasNext();
                          if (b) {
                              np = Objects.requireNonNull(iterator.next(), "The iterator returned a null Nono");
                          }
                      } catch (Throwable ex) {
                          Exceptions.throwIfFatal(ex);
                          if (errors != null) {
                              errors.tryAddThrowableOrReport(ex);
                              errors.tryTerminateConsumer(downstream);
                          } else {
                              downstream.onError(ex);
                          }
                          return;
                      }
                      if (!b) {
                          if (errors != null) {
                              errors.tryTerminateConsumer(downstream);
                          } else {
                              downstream.onComplete();
                          }
                          return;
                      }
                      active = true;
                      np.subscribe(this);
                  }
              } while (wip.decrementAndGet() != 0);
          }
      }
  }
  